Derivative Instruments (Narrative) (Details) - USD ($)		3 Months Ended
		Mar. 31, 2026	Dec. 31, 2025	Dec. 31, 2021
Derivative [Line Items]
Derivative, Notional Amount		$ 5,182,136,000	$ 4,593,942,000
Derivative Asset	[1]	58,399,000	51,421,000
Fair Value Hedging | Loans
Derivative [Line Items]
Carrying Value of Hedged Items		136,300,000
Interest rate swaps
Derivative [Line Items]
Derivative, Notional Amount		2,063,942,000	1,968,679,000
Variation Margin Impact to Positive Fair Values of Cleared Swaps		0
Interest rate swaps | Fair Value Hedging
Derivative [Line Items]
Derivative, Notional Amount		100,000,000.0
Interest Rate Floor [Member]
Derivative [Line Items]
Derivative, Notional Amount		$ 2,500,000,000	$ 2,000,000,000
Derivative, Description of Terms		As of March 31, 2026, the Company held five interest rate floors indexed to 1-month SOFR to hedge the risk of declining interest rates on certain floating rate commercial loans. The floors have a combined notional value of $2.5 billion. Each of the five interest rate floors has a six-year term and a notional amount of $500.0 million. In the event that the index rate falls below zero, the maximum rate that the Company can earn on the notional amount of each floor is limited to the strike rate.
Derivative, Premium Paid		$ 102,200,000
Maximum Length of Time Hedged in Interest Rate Cash Flow Hedge		6 years 6 months
Unrealized gain (loss) on interest rate cash flow hedges, pretax, amount recorded in accumulated other comprehensive income		$ 24,900,000
Cash Flow Hedge Gain (Loss) to be Reclassified within Twelve Months		14,000,000.0
Monetized Interest Rate Floor [Member]
Derivative [Line Items]
Derivative, Notional Amount				$ 1,500,000,000
Cash Flow Hedge Gain (Loss) to be Reclassified within Twelve Months		5,600,000
Derivative Asset				$ 163,200,000
Derivative Instruments, Gain (Loss) Reclassification from Accumulated OCI to Income, Estimated Net Amount to be Transferred		$ 5,600,000
Derivative Instruments, Gain (Loss) Reclassification from Accumulated OCI to Income, Estimate of Time to Transfer		9 months
March 24, 2026 Floor
Derivative [Line Items]
Derivative, Premium Paid		$ 11,900,000

[1] * The fair value of each class of derivative is shown in Note 12.